New GDA2020 Geocoordinate Systems in CE - how does it work?

Hi,

Can someone explain how the newly added Projected Australian GDA2020 GCS works in Microstation CE U11?

We have the old GDA94 GCS group, a new GDA94-7P (7 Parameter Transformation to 2020), GDA94/GSB (GDA94 to 2020 using Grid Shift files) and a plain GDA2020 GCS group. If I reproject the data from the old GDA94 to the GDA-7P or GDA95/GSB GCS settings my data moves as expected, however nothing happens if I go from the old GDA94 to the new GDA2020.

How is this supposed to work?

Regards,

Mark

Parents
  • Mark,

    In order to migrate from GDA94 to GDA2020 you must first change or correct the Geographic Coordinate System from the GDA94 system, to the equivalent based on GDA94/GSB -- without reprojecting. This is a Correction from a coordinate system that used to be based on WGS84 to something that is not anymore (GDA94 used to be considered coincident to WGS84. Now it is GDA2020 that is considered coincident to WGS84 but we cannot change the definition of GDA94 after its existence).

    Once that is done you can reproject to the GDA2020-based Geographic Coordinate System.

    So your process will be a two-step process; 1. Correct the Geographic Coordinate System, do not reproject the data.  2. Reproject the data



    Answer Verified By: Mark Shamoun 

Reply
  • Mark,

    In order to migrate from GDA94 to GDA2020 you must first change or correct the Geographic Coordinate System from the GDA94 system, to the equivalent based on GDA94/GSB -- without reprojecting. This is a Correction from a coordinate system that used to be based on WGS84 to something that is not anymore (GDA94 used to be considered coincident to WGS84. Now it is GDA2020 that is considered coincident to WGS84 but we cannot change the definition of GDA94 after its existence).

    Once that is done you can reproject to the GDA2020-based Geographic Coordinate System.

    So your process will be a two-step process; 1. Correct the Geographic Coordinate System, do not reproject the data.  2. Reproject the data



    Answer Verified By: Mark Shamoun 

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